Biological Availability of Ophthalmic Preparations2. Ophthalmic Therapeutic Systems

Overview

Ophthalmic therapeutic systems, which rank among the drugs of the second and third generation,make possible prolonged and controlled drug release, or the introduction of the drug direct into thesite of action (a specific eye tissue) with minimal distribution into the adjacent tissues. The groupmainly consists of solid ophthalmic preparations, in a lesser extent there are systems developedfromhydrogels, colloidal carriers, etc.The present review lists both insoluble ophthalmic therapeuticsystems and those soluble inwater (degradable, erodible). Insoluble systems includemembrane–controlledophthalmic therapeutic systems (e.g. Ocusert®), therapeutic eye lenses, eye implants, andother insoluble preparations. In the group of soluble preparations, topical inserts and systems aredescribed, which are introduced into eye tissues as implants or injections.

Key words:
ophthalmic therapeutic systems – biological availability – eye inserts –therapeutic eye lenses – eye implants